21384504 has 48 divisors (see below), whose sum is σ = 61326720. Its totient is φ = 6708480.

The previous prime is 21384479. The next prime is 21384509. The reversal of 21384504 is 40548312.

It is a super-2 number, since 2×21384504² = 914594022652032, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21384509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7512 + ... + 9959.

It is an arithmetic number, because the mean of its divisors is an integer number (1277640).

Almost surely, 2^21384504 is an apocalyptic number.

21384504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21384504 is an abundant number, since it is smaller than the sum of its proper divisors (39942216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21384504 is a wasteful number, since it uses less digits than its factorization.

21384504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17500 (or 17493 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 21384504 is about 4624.3382229244. The cubic root of 21384504 is about 277.5660811705.

The spelling of 21384504 in words is "twenty-one million, three hundred eighty-four thousand, five hundred four".